The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 87

ToughBowtieTruck · 01-21-2010, 01:13 AM

Yes 89 is electronic, however, I know there is some way to reconfigure it, as my OBD-I 95 speedometer reads about 5 mph fast now when I put stock tires back on it (so someone had it calibrated for big tires at some point) . . .

No, they are not a direct swap, as the 88-98 c/k bodies are different from the 87 R bodies and 73-86 C bodies (R was 2wd code as the 88-98 bodies were to take the new C code for 2wds--the 87-91 R and 81-86 C are the same body truck, 2wd 81-87 style body, but since crew cabs, suburbans, blazers were built into 1991 those also took the R (2wd) and V (4x4) coding).

The 88-98 C/K frames are wider than the 87 R/73-86 C trucks, so the spring perches would have to be moved. Some axles have both perches but not likely on an 87 truck.

Shock mounts may or not be different also.

If both axles are 10 bolts, the drive shaft should bolt up, though.

01-21-2010, 01:13 AM	#3
ToughBowtieTruck Registered User Join Date: Dec 2009 Location: MI Posts: 111	Re: 87 - 89 Rearend Swap Yes 89 is electronic, however, I know there is some way to reconfigure it, as my OBD-I 95 speedometer reads about 5 mph fast now when I put stock tires back on it (so someone had it calibrated for big tires at some point) . . . No, they are not a direct swap, as the 88-98 c/k bodies are different from the 87 R bodies and 73-86 C bodies (R was 2wd code as the 88-98 bodies were to take the new C code for 2wds--the 87-91 R and 81-86 C are the same body truck, 2wd 81-87 style body, but since crew cabs, suburbans, blazers were built into 1991 those also took the R (2wd) and V (4x4) coding). The 88-98 C/K frames are wider than the 87 R/73-86 C trucks, so the spring perches would have to be moved. Some axles have both perches but not likely on an 87 truck. Shock mounts may or not be different also. If both axles are 10 bolts, the drive shaft should bolt up, though. __________________ -Josh "Mr. Simpson, there are thousands of people like you with no discernible talent." Duff World Records Division "Yeah, they're called Congress!!" -Homer Simpson Last edited by ToughBowtieTruck; 01-21-2010 at 01:15 AM.